Fix output header config not applied to bundled client files

Co-authored-by: mrlubos <12529395+mrlubos@users.noreply.github.com>

Author: Copilot

packages/openapi-ts/src/generate/__tests__/client.test.ts

@@ -1,5 +1,51 @@
 import path from 'node:path';
 
+/**
+ * Replicates the outputHeaderToPrefix logic from generate/client.ts for testing.
+ */
+function outputHeaderToPrefix(header: unknown): string {
+  if (header == null || typeof header === 'function') return '';
+  const lines = Array.isArray(header)
+    ? (header as string[]).flatMap((line) => line.split(/\r?\n/))
+    : (header as string).split(/\r?\n/);
+  const content = lines.join('\n');
+  return content ? `${content}\n\n` : '';
+}
+
+describe('outputHeaderToPrefix logic', () => {
+  it('returns default comment for string header', () => {
+    const result = outputHeaderToPrefix('// This file is auto-generated by @hey-api/openapi-ts');
+    expect(result).toBe('// This file is auto-generated by @hey-api/openapi-ts\n\n');
+  });
+
+  it('returns joined lines for array header', () => {
+    const result = outputHeaderToPrefix([
+      '// This file is auto-generated by @hey-api/openapi-ts',
+      '// @ts-nocheck',
+    ]);
+    expect(result).toBe(
+      '// This file is auto-generated by @hey-api/openapi-ts\n// @ts-nocheck\n\n',
+    );
+  });
+
+  it('returns empty string for null header', () => {
+    expect(outputHeaderToPrefix(null)).toBe('');
+  });
+
+  it('returns empty string for undefined header', () => {
+    expect(outputHeaderToPrefix(undefined)).toBe('');
+  });
+
+  it('returns empty string for function header', () => {
+    expect(outputHeaderToPrefix(() => '// dynamic')).toBe('');
+  });
+
+  it('handles string with embedded newlines', () => {
+    const result = outputHeaderToPrefix('// line1\n// line2');
+    expect(result).toBe('// line1\n// line2\n\n');
+  });
+});
+
 describe('isDevMode logic', () => {
   const scenarios: ReadonlyArray<{
     description: string;

packages/openapi-ts/src/generate/client.ts

@@ -3,7 +3,7 @@ import path from 'node:path';
 import { fileURLToPath } from 'node:url';
 
 import type { IProject, ProjectRenderMeta } from '@hey-api/codegen-core';
-import type { DefinePlugin } from '@hey-api/shared';
+import type { DefinePlugin, OutputHeader } from '@hey-api/shared';
 import { ensureDirSync } from '@hey-api/shared';
 
 import type { Config } from '../config/types';
@@ -53,6 +53,20 @@ function getClientBundlePaths(pluginName: string): {
   };
 }
 
+/**
+ * Converts an {@link OutputHeader} value to a string prefix for file content.
+ * Returns an empty string when the header is null, undefined, or a function
+ * (functions require a render context which is not available for bundled files).
+ */
+function outputHeaderToPrefix(header: OutputHeader): string {
+  if (header == null || typeof header === 'function') return '';
+  const lines = Array.isArray(header)
+    ? header.flatMap((line) => line.split(/\r?\n/))
+    : header.split(/\r?\n/);
+  const content = lines.join('\n');
+  return content ? `${content}\n\n` : '';
+}
+
 /**
  * Returns absolute path to the client folder. This is hard-coded for now.
  */
@@ -114,11 +128,13 @@ function renameFile({
 
 function replaceImports({
   filePath,
+  header,
   isDevMode,
   meta,
   renamed,
 }: {
   filePath: string;
+  header?: string;
   isDevMode?: boolean;
   meta: ProjectRenderMeta;
   renamed: Map<string, string>;
@@ -148,9 +164,10 @@ function replaceImports({
     return replacedMatch;
   });
 
-  const header = '// This file is auto-generated by @hey-api/openapi-ts\n\n';
+  const fileHeader =
+    header !== undefined ? header : '// This file is auto-generated by @hey-api/openapi-ts\n\n';
 
-  content = `${header}${content}`;
+  content = `${fileHeader}${content}`;
 
   fs.writeFileSync(filePath, content, 'utf8');
 }
@@ -159,18 +176,21 @@ function replaceImports({
  * Creates a `client` folder containing the same modules as the client package.
  */
 export function generateClientBundle({
+  header,
   meta,
   outputPath,
   plugin,
   project,
 }: {
+  header?: OutputHeader;
   meta: ProjectRenderMeta;
   outputPath: string;
   plugin: DefinePlugin<Client.Config & { name: string }>['Config'];
   project?: IProject;
 }): Map<string, string> | undefined {
   const renamed = new Map<string, string>();
   const devMode = isDevMode();
+  const headerPrefix = outputHeaderToPrefix(header);
 
   // copy Hey API clients to output
   const isHeyApiClientPlugin = plugin.name.startsWith('@hey-api/client-');
@@ -211,6 +231,7 @@ export function generateClientBundle({
     for (const file of coreFiles) {
       replaceImports({
         filePath: path.resolve(coreOutputPath, file),
+        header: headerPrefix,
         isDevMode: devMode,
         meta,
         renamed,
@@ -221,6 +242,7 @@ export function generateClientBundle({
     for (const file of clientFiles) {
       replaceImports({
         filePath: path.resolve(clientOutputPath, file),
+        header: headerPrefix,
         isDevMode: devMode,
         meta,
         renamed,

packages/openapi-ts/src/generate/output.ts

@@ -24,6 +24,7 @@ export async function generateOutput(context: Context): Promise<void> {
     // not proud of this one
     // @ts-expect-error
     config._FRAGILE_CLIENT_BUNDLE_RENAMED = generateClientBundle({
+      header: config.output.header,
       meta: {
         importFileExtension: config.output.importFileExtension,
       },